1. Field of the Invention
The present invention relates to a connector provided on a camera body, an interchangeable lens, an accessory or the like (hereinafter collectively called components) constituting a camera system and serving to electrically connect such components.
2. Related Background Art
In conventional camera systems, there has widely been employed a rotary bayonet mount for effecting attachment and detachment of the components. Such rotary bayonet mount is designed to effect attachment or detachment of the components by relative clockwise or anticlockwise rotation of the components.
In such camera system, each component is provided with an electric circuit, and information (for example that for automatic exposure control) is exchanged between the components. For such information exchange, a connector having plural contact pins is provided in the vicinity of the mount of each component.
Such a conventional connector as mentioned above will be explained in the following.
The connector comprises an upper cover, a lower cover, contact springs positioned between these covers and provided with the above-mentioned contact pins, and a conductive pattern bearing member provided with the above-mentioned electrical circuit to be connected to the contact springs.
Such a conventional connector is assembled by placing the contact springs and the conductive pattern bearing member in succession on the upper cover, thereby bringing the two in mutual contact and forming an electrical connection therebetween, then placing the lower cover in superposition with the upper cover so as to sandwich the contact springs and the conductive pattern bearing member therebetween, and providing ultrasonic vibration to heat and fuse the contact face of the upper and lower covers, thereby achieving fixation. In this manner the upper and lower covers are mutually connected and the connector is completed.
In the above-mentioned conventional connector, however, the biasing force of the contact springs is exerted in a direction to mutually separate the upper and lower covers (this force being hereinafter called a separating force), so that, if a large number of contact springs are provided on the circumference of the connector, the separating force becomes larger to render the fused fixation of the upper and lower covers difficult. Also, the fused portion may deteriorate in time, eventually resulting in separation of the upper and lower covers.
In order to overcome the above-mentioned drawbacks, the present inventors already proposed to provide the upper and lower covers respectively with engaging parts and to cause mutual engagement of such engaging parts by a sliding motion of the lower cover relative to the upper cover, thereby achieving mutual connection of the two (Japanese Patent Application No. 4-162578).
However, such sliding motion of the lower cover relative to the upper cover tends to displace the conductive pattern bearing member together with the lower cover, so that it has been difficult to mount the lower cover while maintaining the conductive pattern bearing member in the predetermined position. Also, the assembly with the conductive pattern bearing member in the displaced state may result in shortcircuiting of the contact pins of the neighboring contact springs.
In addition, the upper and lower covers have to be securely fixed, for example, with screws. However, if the above-mentioned separating force is large when the covers are made, for example, of a plastic material, the female threads formed therein may be damaged by such a separating force. Conseuqently, the cover bearing such female threads has to be made of a metal material, in consideration of the mechanical strength.
However, if the cover is made of metal, burs on the cut sections of plating leads of conductive patterns on the conductive pattern bearing member may touch such a metallic cover, thus causing defective electrical contact. For avoiding such drawback, it is conceivable to apply an insulating tape between the cover made of metallic material and the conductive pattern bearing member, or to form the plating leads of the conductive pattern bearing member in other positions. However, such application of the insulating tape will lead to a drawback of an assembling operation having a reduced efficiency and an elevated cost, while limitation in the position of the plating leads will result in another drawback of reduced freedom in the designing of the conductive pattern bearing member.